This dataset contains data from:

E. Keith Bowers, Pavel Munclinger, Stanislav Bureš, Lenka Kučerová, Petr Nádvorník, and Miloš Krist: Cross-fostering eggs reveals that female collared flycatchers adjust clutch sex ratios according to parental ability to invest in offspring. Molecular Ecology.

Data collector: Miloš Krist, e-mail: milos.krist@upol.cz

Dataset is saved as CSV file separated by semicolons. There are no special symbols for missing data. Missing data are simply empty cells in the spreadsheed. Each row contains data for different chick. Some columns contain data on the nest level, so here values are the same for all siblings. All data from 2006-2009 relate to original nests and parents that produced offspring (i.e. laid eggs), not those that cared for them in a nestling stage. 

The dataset has following columns:

1) Year - year of the study.
2) Original_nest - identity of the nest of offspring origin. This is composed from the year (the first two numbers), study plot (a letter), and nest-box number (numbers following the letter). 
3) Rearing_nest - identity of the nest where the offspring has been raised. This is composed from the year (the first two numbers), study plot (a letter), and nest-box number (numbers following the letter).
4) Female_ring - identity of female parent.
5) Male_ring - identity of male parent.
6) Offspring_ring - identity of offspring. Not given for 2001-2002 part of dataset.
7) Laydate - laying date. Julian date (1 = 1st January).
8) Clutch_size
9) Chick_mass - mean mass (in grams) of foster offspring at age 13 days (day of hatching = 0) that were raised in nests whose identities are given in column "Original_nest". Only values of offspring that subsequently fledged were included in calculations of brood means.
10) Male_age - binary variable describing whether male parent was one year old or older.
11) Male_wing_patch - sum of length of visible white on outer webs of 3 to 8 primaries (in mm).
12) Male_forehead_patch - area of white forehead patch (in mm2) scored from digital photograph (in 2007-2009) or predicted from linear dimensions (2001-2006).
13) Female_age - female age in years. Not given for 2001-2002 part of dataset. For females ringed as nestlings this is exactly known. Females, that were ringed only as adults, were considered to be one year old at their first capture. So for these females, values represent their minimal age. 
14) Exact? - binary variable describing whether age of female was known (exact) or estimated (minimal).
15) Laying_order - egg number in laying sequence.
16) Egg_size - volume of egg from which offspring was hatched (in mm3).
17) Paternity - offspring paternity (w = offspring sired by the social partner, e = offspring sired by an extra-pair partner).
18) Sex - offspring sex (m = male, f = female).
19) Number_of_males - number of males produced in original nest. "Event" in logistic regression.
20) Number_determined - number of offspring produced in original nest for which sex was determined. "Trial" in logistic regression.
21) Primary sex ratio - values from a column 19 divided by values from a column 20.
22) Foster_sex_ratio - brood sex ratio of all (both fledged and unfledged) foster young that were raised in nests whose identities are given in column "Original_nest".